MSPs clashed over the huge sums paid to pharmacists to dispense the controversial heroin substitute.

In a string of exclusives, we’ve revealed how methadone costs taxpayers more than £36million a year but no data is kept on whether it is working or not.

We also discovered that some addicts have been parked on methadone for a staggering three decades.

The pressure we exerted eventually forced the SNP Government to order a probe into treatment.

And yesterday, our revelations dominated debate at the Scottish Parliament and forced a rethink on how Scotland deals with its devastating drug problem.

Speaking in the Holyrood chamber, Labour MSP Jenny Marra backed our campaign and warned that addicts can become “stranded” on the substance without help to get clean.

She insisted that money could be better spent on residential treatment and claimed the Government’s drug strategy is “unravelling”.

Marra said: “While we recognise the advantages that methadone brings as one part of a comprehensive drugs strategy, we need to know that public money is being spent to do more than simply strand addicts in the system. That won’t let all of them recover.”

She also pointed out that pharmacists across Scotland get paid different amounts for dispensing meth-adone, saying: “We don’t believe this is fair, and we don’t believe the Scottish people do either.

“We believe that in its review, the Government should look at the allocation of public resources to the drugs strategy and ask what measures can be taken to address this postcode anomaly.”

The Record revealed yesterday that in the Borders, where methadone use is comparatively low, pharmacists receive £1.75 for each dose they give – but in Ayrshire and Arran, one of the worst affected areas, the fee rises to £2.49.

Community Safety Minister Roseanna Cunningham defended the methadone programme as part of the Government’s Road to Recovery drug strategy.

She said: “Does methadone reduce drug-related deaths, blood-borne viruses and crime? We know it does. Does it stabilise lives? Yes, it does.

“But methadone is only one of a number of treatment options. We are clear it can be effective but only as a component in a package of care, treatment and recovery.”

After the Record’s extensive coverage of the methadone programme in recent months, an independent expert panel led by Chief Medical Officer Sir Harry Burns will meet for the first time today to probe use of the drug.

Labour MSP Graeme Pearson, a former director general of the Scottish Crime and Drug Enforcement Agency, said: “During the last five years, 2643 people have died as a result of a drug overdose – a record number unfortunately dying in this last year alone.

“There has been £8million spent on methadone and a further £28million spent delivering methadone in 2011. That’s a rise of 36 per cent from the 2007 sum and a nine per cent increase in the number of prescriptions – 22,000 people a year are prescribed it as an alternative to heroin.

“A United Nations statistic still shows Scotland at the high end of usage and a shame to ourselves as a country.”

But SNP MSP Jamie Hepburn rejected the idea that pharmacists are profiteering from the methadone programme.